The Jefferson County Coroner's Office identified the victims as Jacky Nguyen, the 60-year-old salon owner, and his common-law wife, Nhut Phan, 50.

Authorities believe the couple were killed during a holdup.

Family members gathered and wept at the crime scene, but declined comment. Customers said Phan had been battling cancer.

"They had been very concerned about that," Cox said. "They were such friendly people. Anybody who came in, they acted like they knew them."

Police said the crime was unconscionable.

"It's such a tragedy for a family to end this year on a note like this," said Birmingham Deputy Chief Herman Hinton. "It's one thing to rob a business, but to take the lives of the owners simply because you can takes this incident to an all-time low."

A female customer went into the business shortly before 9 a.m. today and took a seat in the front waiting area. Nguyen's Lincoln Navigator was parked in its usual spot out front.

Neither Nguyen nor Phan came out from the rear office, like they usually do when a customer enters, so the customer used her cell phone to call the salon number but got no answer, authorities said.

When two employees came in, they walked toward the rear of the business and found the bodies.

Nguyen was on the floor slumped against a wall in the rear of the salon portion, police said. Phan was sitting in a chair in the back office, shot multiple times.

There was no forced entry, and police believe the two may have been killed as early as Sunday evening, possibly around 6 p.m. Sunday, which was closing time for the salon.

They were last seen alive at about 4 p.m., when other workers finished for the day and left the salon.

The back door of the business was locked, police said. A video surveillance camera in the store was running but not recording, police said.

Investigators canvassed area businesses to collect their surveillance camera videos, which they will study to see whether there are images of the killer or killers entering or leaving the nail salon.

Otherwise, detectives said, they have few clues. They need anyone who heard or saw anything unusual near the business to come forward.

"We are issuing a plea for the public's assistance," said Birmingham homicide Sgt. Scott Thurmond. "It's just a senseless act that these people lost their lives over possibly a small amount of money they had in their store. They were in there working, trying to make a living."

Anyone with information is asked to call Birmingham police at 254-1764 or the anonymous Crimestoppers tipline at 254-7777.

"These thugs were way out of bounds," Hinton said. "Hopefully we can bring a semblance of closure to this incident by finding the assailants responsible and bringing them to justice."